An airbag apparatus equipped with no flanges for attachment and securement purposes is known in the art (see Patent Document 1, for example). This airbag apparatus includes a cylindrical inflator for generating gas, a retainer serving as a base member, an airbag to inflate with the gas generated by the inflator, and a bag ring for securing the perimeter of the opening of the airbag to the retainer. The bag ring includes a cylindrical part to support the end faces of the inflator in the axial direction thereof and a flange part extending in the radial direction from the cylindrical part.
In an example of the airbag apparatus described above, the flange part of the bag ring has a plurality of pins at the edge thereof bendable in the radial direction, and both the airbag and the retainer have a plurality of penetrating holes penetrating therethrough in the axial direction in one-to-one correspondence with the pins of the bag ring. In this structure, the pins of the flange part of the bag ring are inserted into the penetrating holes of the airbag and the retainer, and the tips of the pins are then bent toward the center axis, so that the bag ring, the airbag, and the retainer are secured together to form an integral whole with the inflator held therein (see FIG. 4 and FIG. 5, for example).
[Patent Document 1] Japanese Patent No. 4560881